The present invention relates generally to disposable absorbent articles, such as baby diapers, training pants, adult incontinence products, feminine hygiene articles, and the like. More particularly, the present invention relates to improved absorbent core components, disposable absorbent articles utilizing such absorbent core components, and a method of making or manufacturing same.
An advantageous application of the various concepts and embodiments of the present invention is one directed to baby diapers. For this reason, much of the exemplary descriptions provided herein are directed to diapers. The invention extends, of course, to applications beyond diapers.
Most absorbent articles used today as baby diapers have a configuration similar to the absorbent article 10 depicted in FIGS. 1A and 1B. The conventional absorbent article 10 is shown in a laid out flat position in FIG. 1A, and in cross sectional view in FIG. 1B. This absorbent article 10 includes an outer-side fluid impermeable backsheet 101, a bodyside, fluid permeable nonwoven coverstock or topsheet 102, and an absorbent construction 110 positioned between the backsheet 101 and topsheet 102. An absorbent core 103 provides the primary component of the absorbent construction 110 and is designed and positioned to receive and retain bodily fluids. The absorbent construction 110 may also include at least one fluid management, fluid distribution and/or surge layer 104a. 
As shown in FIG. 1A, the backsheet 101 and topsheet 102 together form or define a chassis or central body 105 of the absorbent article 10. The central body 105 may be described as having a first longitudinal end edge 112a, a second longitudinal end edge 112b, and a longitudinal centerline YY that extends through the central body 105, bisecting both the first and second end edges 112a, 112b. Left and side margins 106a, 106b extend from one end edge 112a to the other end edge 112b. Each end edge 112a, 112b partly defines waist regions 113a, 113b of the central body 105 which are generally characterized as having a lateral width significantly greater than a lateral width of a central region or crotch region 114 of the central body 105. The waist regions 113a, 113b are designed to allow the absorbent article 10 to be placed about the waist of the user. In this respect, the first and second waist regions 113a, 113b may be described as front and rear waist regions 113a, 113b, respectively. The conventional absorbent article 10 further includes a fastening means 104 attached to each side of the rear waist region 113a. The fastening means 104 are extendible and thereby, fastenable to a corresponding side of the front waist region 113b. The fastening means 104 helps to retain the article 10 around and on the body of the user. The absorbent article 10 also includes a means for elasticizing 107 the article 10 to maintain closure and sealing around the user's legs. The elasticizing means 107 (e.g., leg cuffs and/or leg cutters) are necessarily positioned outboard of and along longitudinal side margins 106a, 106b of the absorbent construction 110. Referring to FIG. 1A, the conventional absorbent core 110 is centrally positioned in and about the crotch region 114 of the absorbent article 10.
Currently, most diaper cores are made from mixtures of fibers and superabsorbent particles, specifically cellulose based fibers derived from wood pulp and superabsorbent particles (SAP) derived from polyacrylic acid derivatives. An absorbent composite that is particularly suited for application in or with the disposable absorbent articles introduced herein is described in U.S. Pat. No. 6,540,853. SAP-nonwoven absorbent composites of the type disclosed in this patent reference are available to the diaper manufacturing process in roll form and allow much greater freedom for the design of absorbent cores. Nevertheless, because fluff pulp-superabsorbent cores are generally provided as a continuous stream or web of absorbent material, the simpler and most cost efficient processes require the absorbent core to be maintained in a generally rectangular shape.
These cores are typically formed into rectangular shapes that are designed for incorporation into an absorbent article. The core shape, particularly its width, is maintained at dimensions that accommodate placement within a diaper corresponding with the crotch area of the user. Moreover, it is preferred in many applications for the absorbent core to take on a nearly hourglass shape. Such diaper cores are known in the art as providing a narrower crotch region that presents a better fit and comfort for the user. The hourglass shape also provides wider regions at the longitudinal ends of the core, which enhances the absorbency and leakage control capability of the diaper at those regions above the central crotch region.
FIG. 1C illustrates another prior art disposable absorbent article 10′. The absorbent article 10′ employs a design in which an absorbent core 110′ is reduced in width in the crotch region 114′, but is wider at the front and rear waist regions 113a′, 113b′. The result is an absorbent core 110′ having a more hourglass shape. To achieve this desired hourglass shaped core, a rectangular absorbent core section is cut from a continuous web of absorbent material and shaped further, particularly in forming the narrow central region.
As known in the art, the preferred diaper assembly process is a substantially linear and efficient machine directed process that produces a high volume of packaged products. Because of the nature of the consumer product as a disposable, high frequency of use item and the abundance of competing products and alternative products (e.g., re-usable cloth diapers), it is imperative to maintain the low cost of the final product. Accordingly, it is also imperative to control the complexity of the manufacturing process and to minimize steps and material waste. This presents a technical challenge to one attempting to create alternative shapes and functionalities in the conventional disposable absorbent article. For example, although an hourglass shaped diaper core is generally desirable or, in some applications, a core having distinct areas of absorbency, additional cutting or forming steps or increased material cost may make the alternative design less effective.
In any event, absorbent core configurations achieving further functionalities and/or improved fit and comfort for the sure are desirable. Caution must be exercised, however, to minimize material cost and manufacturing complexity.